Answer:
Han= 24 minutes
His sister= 24 minutes
His Dad= 36 minutes
Grandmother= 42 minutes
Step-by-step explanation:
Please see attached picture for full solution.
Where the working split, see the right hand side.
The question states that Han's Dad sits 1.5 times as long as both Han and his sister. There could be 2 interpretations for this:
- Dad sits for 1.5 times of (Han and his sister)
- Dad sits for 1.5 times of Han and 1.5 times of Han's sister
I've done the working for both scenarios and found out that the 1st case cannot be true since Dad would've sat for 50.4 minutes when the bus ride is only 42 minutes! Moreover, there wouldn't be enough information to know how long Han and his sister sat for.
The second case is possible and it's working is on the right.
Feel free to ask if you have any enquiries :)
Answer:
50
Step-by-step explanation:
575/11.5=50
Answer:
x = 8,49 ft
y = 4,24 ft
Step-by-step explanation:
Let x be the longer side of rectangle and y the shorter
Area of rectangle = 36 ft² 36 = x* y ⇒ y =36/x
Perimeter of rectangle:
P = 2x + 2y for convinience we will write it as P = ( 2x + y ) + y
C(x,y) = 1 * ( 2x + y ) + 3* y
The cost equation as function of x is:
C(x) = 2x + 36/x + 108/x
C(x) = 2x + 144/x
Taking derivatives on both sides of the equation
C´(x) = 2 - 144/x²
C´(x) = 0 2 - 144/x² = 0 ⇒ 2x² -144 = 0 ⇒ x² = 72
x = 8,49 ft y = 36/8.49 y = 4,24 ft
How can we be sure that value will give us a minimun
We get second derivative
C´(x) = 2 - 144/x² ⇒C´´(x) = 2x (144)/ x⁴
so C´´(x) > 0
condition for a minimum
If he went 36 miles in 3 hours, he rode at a speed of 12 miles per hour (36/3=12). So if he rode his bike at that same speed for 5 hours he would go 60 miles (12x5=60).
Answer:
4 pi
Step-by-step explanation:
diameter = 2r
4 =2r
r =2
area = pi × (r)^2
= pi × 2^2
= 4 pi
